Hillary Clinton is packing her campaign schedule with new stops across California ahead of next week’s delegate-rich primary, in an apparent bid to forestall a Bernie Sanders win as her rival climbs in the polls and barnstorms the state in pursuit of a dramatic upset.

The campaign hastily scrapped a planned New Jersey stop later in the week, and instead announced the Democratic presidential front-runner will camp out in California from Thursday through Monday, right up until the June 7 primary.

In a boost ahead of her West Coast swing, Clinton also snagged the endorsement Tuesday of California Gov. Jerry Brown, who in an “open letter” said Clinton represents “the only path forward to win the presidency and stop the dangerous candidacy of Donald Trump.”

He wrote, “Hillary Clinton has convincingly made the case that she knows how to get things done and has the tenacity and skill to advance the Democratic agenda.”

The developments come amid signs that the campaign-finale contest could be close. A recent poll, by the Public Policy Institute of California, showed Clinton’s lead in the state narrowing from double digits to just 2 points. Sanders, meanwhile, has been crisscrossing California for days and on Monday boldly predicted a victory in the Golden State, where 475 pledged delegates are at stake.

“She’s getting very nervous lately,” Sanders claimed of Clinton.  

Clinton does not have to be nervous about whether she’ll effectively secure the nomination by June 7 – she’s just 71 delegates shy of the 2,383 needed to clinch, and is assured of crossing that threshold by next Tuesday night. Six states, including California and New Jersey, are voting on Tuesday, the last major primary election day.

But she wants to avoid a high-profile loss in the Democratic stronghold, at a time when she's trying to unify the party. A Sanders upset victory could energize the Vermont senator’s vows to take his fight all the way to the convention.

Speaking Monday in Oakland, Calif., Sanders insisted the race will not be over next Tuesday. He again vowed to keep working to persuade so-called superdelegates – party insiders and officials free to support any candidate – to cross over to his side in the weeks ahead. (While Clinton is sure to exceed the 2,383-delegate threshold on Tuesday, Sanders' campaign for weeks has questioned whether her superdelegate support should count toward that tally.) 

On Tuesday, Sanders was continuing his extended swing through California with stops in Emeryville, Santa Cruz and Monterey.

Clinton has not revealed exact details on where she’ll be campaigning when she travels from New Jersey to California later in the week.

Her attention to New Jersey in recent days may reflect the campaign’s back-up plan in case California is tight. Clinton aides recently told Fox News they're hoping for an overwhelming win in New Jersey‎ on June 7, which could possibly seal the nomination for Clinton before the polls even close in California.

"If things go our way in New Jersey," one senior Clinton official said, "we could wrap up the nomination and the rest of the country will already be asleep before the results are even final in California."

Sanders aides told Fox News they plan to spend most of their time in California in the lead-up to Tuesday and feel they are closing strong in the nation's most populous state.

"We feel it's an important state," Sanders spokesman Michael Briggs told Fox News. "And we plan to campaign hard there and turn these huge crowds and momentum into a big win."

Fox News’ Jake Gibson and Dan Gallo contributed to this report.